JPS6329069A - Cryopump - Google Patents

Abstract

PURPOSE:To make it possible to facilitate the regulation of exhaust capacity and to eliminate detrimental effects by Ar, N2 and the like, by thermally insulating each adjacent split panels from each other and by enabling the respective split panels to be heated optionally. CONSTITUTION:In a refrigerator 1, respective heaters 8a-8f attached to split panels 6a-6j may be optionally heated under control by means of a control device 12. With this arrangement, the exhaust capacity for Ar, N2 and O2 may be optionally regulated in such a range that the absorbing area of the second panels 6 are divided. Further, Ar, N2 and O2 emitted from heated second panels 6 are absorbed by the other second panels 6 having not yet heated, and therefore it is possible to prevent the absorbing capacity for He and H2 from being lowered due to absorption of Ar, N2 and O2 into absorbent for absorbing He and H2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cryopump, and particularly to a multi-lyopump suitable for varying the pumping speed.

[Conventional technology]

In the conventional apparatus, as described in Japanese Patent Application Laid-Open No. 60-204981, the temperature of the entire second stage cryopanel was adjusted to control the adsorption and exhaust capacity.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into account the ease of controlling the exhaust capacity, and although it is possible to reduce the exhaust capacity, it is not possible to finely adjust the exhaust capacity. That is, the sixth
As shown in the figure, when the second stage cryopanel is heated, the temperature of the second stage cryopanel changes by about 29 to 34. Because the exhaust capacity changes rapidly from 100 inches to 10%, it is difficult to accurately control the 'iE two-stage glio bomb at temperatures around IK. Therefore, fine adjustment of the exhaust capacity is extremely difficult. Ta.

Furthermore, when the temperature of the second glyopal is increased, the condensation equilibrium conditions for Ar and N2 that have been condensed and captured on the panel surface are destroyed, and Ar and N2 are released. In this case, since the entire surface of the second glioblast remains at almost the same temperature, the released Ar and N2 gases are not recondensed (for example,
The saturated vapor pressure of N2 at
rr, and the cryopump operating pressure I x 10-
It does not condense at 8 to 10-9 Torr. ), these gases are adsorbed by the adsorbent attached to the inside of the second stage gliopanel, which adsorbs and traps gases with higher saturated vapor pressures such as He and N2. There has been a problem in that the ability to exhaust He, N2, etc., is reduced.

Furthermore, there is a problem in that the N2 gas remaining without being adsorbed by the adsorbent has an adverse effect on processes in, for example, sputtering equipment of semiconductor manufacturing equipment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a Talio pump that can easily adjust the exhaust capacity and eliminate the adverse effects of Ar, N2, etc.

[Means for solving problems]

The above purpose is to divide the panel into multiple parts, thermally isolate adjacent panels from each other, and optionally separate each panel in a Talio pump that has a panel that is cooled below the temperature of liquid hydrogen in a vacuum atmosphere. This is achieved by providing a heating means capable of heating the temperature.

[For production]

Each of the panels, which has been cooled to below the temperature of liquid hydrogen and divided into multiple pieces, is heated and maintained at a temperature that destroys the condensation equilibrium conditions of Ar and N2. Ar and N2 are not adsorbed, and other parts of the panel are cooled and adsorb Ar and N2. This reduces the adsorption amount of Ar and N2, making it possible to vary the exhaust capacity.
Ar and N2 released from the heated panel are adsorbed by other cooled panel parts and do not reduce the adsorption ability of the adsorbent for adsorbing HetH2.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. This will be explained using diagram J2.

The refrigerator 1 has a first cold stage 2 that can be cooled to below 100K, and a second cold stage 3 that can be cooled to below 20K (liquid hydrogen temperature).

A second panel 6 is attached to the second cold stage 3, and as shown in FIG. 1, it is divided into, for example, six equal parts by a slit 13 into second panels 6a and 6b.

A first panel 5 formed to surround a second panel 6 is attached to the first cold stage 2 . moreover,
The vacuum layer 4 formed to surround the first panel 5 freezes! 1 is installed.

A buckle 7 supported by the first panel 5 is provided at the upper part of the second panel 6 in the drawing. The vacuum layer 4 has a flange at the top shown in the figure, and is attached to an evacuated chamber (not shown).

Heaters 8a to 8f, which are heating means, are attached to the inside of the second panels 6a to 6f, respectively, and are connected to lead wires 9 and U via connectors such as hermetic seals 10 attached to the vacuum layer 4. It is connected to the control device t12.

With the above configuration, the first panel 5 and the baffle 7 connected to the first cold stage 2 are cooled to below 100 ℃, adsorb and condense moisture and carbon dioxide gas, which are mainly removed by the puffful 7 and passed through the baffle 7. Moisture and carbon dioxide are removed by the first panel 5.

The second panel 6 connected to the second cold stage 3 has two
Ar is mainly cooled to below 0 on the outer surface of the second panel 6
HN2*02 is absorbed and condensed with He, which cannot be adsorbed.
N2 is adsorbed and removed by an adsorbent (not shown) attached to the inside of the second panel, and is removed from the evacuated chamber (not shown) and the vacuum layer 4.
Rub the inside with high vacuum.

At this time, the heaters 8a to 8f attached to the second panels 6a to 6f are arbitrarily selected by the control device 11 and heated to a temperature that destroys the condensation equilibrium condition of Ar and N2.02. For example, heater 8a.

If 8C and 8C are heated, the second panel 6a.

Arl N2+ o2 is released from 6c and 6e,
Ar, N210 for second panels 6a, 6c and 6C
2 is not adsorbed, and the surfaces that adsorb Ar and N2.02 are the second panels 6b, 6d and 6f, and the adsorbable area is in this case t/2c 'tc IJ, Ar l N21
02 'k Intake 'It Since the ability to exhaust air is also reduced to 1/2, the overall exhaust ability is also reduced.

In this way, by changing the number of second panels 6a to 6f that can be heated, the exhaust capacity of Ar and N2+02 can be arbitrarily varied. Furthermore, which second panel is to be heated is determined by the control device W12.

Further, for example, the heated second panel 6a described above,
Arl N2102 released from 6c and 6e is
Since the A released from the second panels 6a, 6b and 6e is adsorbed by the cooled second panels 6b, 6d and 6e, the adsorbent adsorbs N2 and N2.
r, N2.02 does not adsorb and prevent He and N2 adsorption.

As described above, according to this embodiment, since the heaters attached to the divided second panels can be heated arbitrarily by the control device, the suction area of the second panel can be arbitrarily adjusted within the divided range, and the exhaust capacity can be adjusted as desired. This has the effect of being able to be adjusted arbitrarily.

Also, Ar released from the heated second panel.

N2,02 is adsorbed by the unheated second panel and adsorbed by the adsorbent for adsorbing He and N2, so that the adsorption capacity for He and Hz is not reduced.

Next, a second embodiment of the present invention will be described with reference to FIG.

In FIG. 3, the same reference numerals as in FIG. 1 indicate the same members, and the difference between this figure and FIG. 2. A second panel 6g with an area of 1/2 of the remaining panel 6, a second panel 8h with an area of 1/2 of the remaining area, and a second panel 81 with an area of 1/2 of the remaining area. 8j
In this case, the second panels 6h, 6i and 6j are provided with heaters sh.

81 and 8j are provided.◎ As a result, the suction area of the second panel 6 becomes 1/2 by heating the second panel 6h, 6it 6j, for example.
If the second panels 6h and 6j are heated, it becomes 5/8, and the second
If panel 6h is heated, it will become 3/4I, and the second panel 6
By heating 1, it becomes 7/8 to 1. By gradually decreasing the divided area in this way, the number of divisions can be reduced and the exhaust capacity can be controlled more precisely than by dividing into equal parts.

Next, a third embodiment of the present invention will be described with reference to FIGS. 4 to 6.

In FIGS. 4 and 5, the same reference numerals as in FIGS. 1 and 2 indicate the same members, and the difference between this figure and FIGS. 1 and 2 is that the heating means of the second panel 6 is 8 is replaced by a mechanism for transmitting the temperature of the first panel 5 to the second panel 6.

in this case,'! Provided between the J1 panel 5 and the second panel 6! A bearing 17 attached to the J1 panel 5,
A shaft 16 is supported by passing through the lower part of the first panel 5 as shown in the figure by a bearing 18 attached to the lower part of the first panel 5, an arm 15 is attached to the upper part of the shaft 16 in the figure, and contact plates are attached to both ends of the arm 15. 14 is attached, and the contact plate 14 is arranged at a position corresponding to adjacent second panels 6b and 6c, 6d and 6e, and 6f and 6a, with gaps provided therebetween. A through hole is provided in the surface of the vacuum layer 40 facing the lower part of the shaft 16 in the figure, and a rotary fitting is attached to the outside of the vacuum layer 4 through the seat 19 at the through hole portion, and the shaft 16 is attached as shown in FIG.
Insert the rotating shaft of the rotating device into the recessed portion at the bottom of the figure, leaving a gap. The rotating device is connected to the control device 1t12 by a lead wire 11a.

With the above configuration, the control device rotates the rotating device, for example, a pulse motor. As a result, there is no gap in the rotational direction at the part where the shaft of the rotating device (9) and the shaft 16 fit together, the shaft of the rotating device (9) and the shaft 16 come into contact, the shaft 16 rotates, and the arm 15 is rotated so that one of the contact plates contacts the second panel, for example 6b, and the second panel 6b is heated by the contact plate cooled to the temperature of the first panel 5.

As described above, according to the third embodiment, since the second panels 6a to 6f can be selected and heated by the control device 12,
Similar to the first embodiment, this embodiment has the advantage that the exhaust capacity can be varied.

In this embodiment, the heater or the temperature of the first panel is used as a means for heating the second panel, but for example, it is also possible to heat the bolts that attach the second panel 6 to the second cold stage 3. This reduces the surface pressure between the second panel 6 and the second cold stage 3, thereby impairing heat transfer.
However, the exhaust capacity can also be varied by preventing any one of the second panels 6a to 6f from being cooled.

In addition, in this embodiment, the second panel is directly connected to the second
Although an integrated type cryopump that cools in a cold stage is described, a separate type cryopump configured by separating the refrigerator and the panel may also be used.

〔Effect of the invention〕

As described above, according to the present invention, the pumping capacity of the cryopump can be easily adjusted, and Ar and N2 are not adversely affected.
It has the effect of being able to

[Brief explanation of drawings]

FIG. 1 is a plan view showing a cryopump that is an embodiment of the present invention, FIG. 2 is a side sectional view of FIG. 1, and FIG. 3 is a plan view showing a cryopump that is a second embodiment of the invention. Figure, 4th
The figure is a side sectional view showing a cryopump that is the third embodiment of the present invention, Figure 5 is a plan view of Figure 4, Figure N6 is a side view of Figure 4 taken from A-A, and Figure fJ7 is a side view of the cryopump according to the third embodiment of the present invention. It is a graph showing the pumping characteristics of a conventional cryopump. 6.6a to 6j...Second panel, 8,8a
to 8f and 8h to 8j... heater,
C: Control device, 14: Contact plate, 1
5...Arm, 16 Fig. 1 Fig. 3 Fig. 4 "t5 Fig.") r6 Fig.

Claims (1)

[Claims] 1. In a cryopump having a panel that is cooled to below the temperature of liquid hydrogen in a vacuum atmosphere, the panel is divided into a plurality of parts, adjacent divided panels are thermally isolated from each other, and the divided panels are A cryopump characterized by being provided with a heating means that can arbitrarily heat each part.